Miniature single-pole double-throw switch



Dec. 13, 1966 KA OU 3,291,951

MINIATURE SINGLEFPOLE DOUBLE-THROW SWITCH Filed Sept. 29, 1964 /4 I FIG 2 20 -I l #tl 1 INVENTOR.

LEO R. KALOUS ATTORNEY United States Patent F 3,291,951 MTURE SWGLE-POLE DOUBLE-TIROW SWITCH Leo R. Kalous, Cedar Rapids, Iowa, assignor to Collins Radio Company, Cedar Rapids, Iowa, a corporation of Iowa Filed Sept. 29, 1964, Ser. No. 400,148 6 Claims. (Cl. 200155) The invention described herein was made in performance of Work under a NASA contract and is subject to the provisions of Section 305 of the National Aeronautics and Space Act of 1958 under which the government has retained a nonexclusive royalty free license.

This invention relates to a miniature single-pole, doublethrow switch.

Present day aircraft and spacecraft are continuously being supplied with a growing amount of electronic equipment. This growing amount of equipment has created a need for light weight and compactness without a sacrifice of operating ease or reliability.

It is therefore an object of this invention to provide a miniature single-pole, double-throw switch having a cammed rotor which positively insures the opening of one contact position and the closing of the other.

It is another object of this invention to provide such a switch wherein the cammed rotor also serves as a detent to prevent a change of" switch position due to vibrations or other undesirable causes.

It is still another object of this invention to provide such a switch wherein the cammed rotor also serves as a stopping means to limit the rotor rotation to a small angle.

Further objects, features, and advantages of the invention will become apparent from the following description and claims when read in view of the accompanying drawings, in which:

FIGURE 1 shows a cross sectional view taken along line 11 of FIGURE 2;

FIGURE 2 is a viewlooking into the switch with the header removed;

FIGURE 3 is a view showing the bottom of the switching device;

FIGURE 4 is a pictorial view of the switching device;

FIGURES 5a and 5b are a detailed showing of the cammed rotor; and

FIGURE 6 is a pictorial view of a leaf spring contact.

Referring to FIGURE 1, a case 11 is provided with a hole 23 in the bottom thereof. As shown in FIGURE 2, the hole 23 is offset from the longitudinal axis such that a b. A cammed rotor 12 having a step portion 24, an instep portion 18, and an offset portion 17 is inserted into hole 23 as shown in FIGURE 1. An O-ring 15 is inserted between offset 17 and case 11. A central contact 13 having integral therewith, a base portion 13' rests in instep portion 18 of rotor 12. Two leaf spring contacts are inserted into case 11 as shown in FIGURE 1 and a header 19 inserted between the leaf springs 14 to hold them against case 11 and also to hold contact 13 against rotor 12. Contact 13 can also be mounted on rotor 12 by extending the narrow portion 13 through the base 13' and inserting the extended portion into a hole provided in rotor 12. This would permit removal of step 24 from the rotor 12 and thereby eliminate the possibility of residue from step 24 preventing a clean contact with a leaf spring contact 14. Also leaf spring contacts 14 could be bifurcated to cause a wiping action with contact 13. Offset Patented Dec. 13, 1966 portion 17 of rotor 12 is equipped with a slot 22 to permit the turning of the rotor 12 with an ordinary screw driver. The bottom of case 11 is supplied with two indicator marks 16 substantially apart. As shown in FIGURES 2 and 5b, rotor 12 has two flat surfaces 20 extending along the length thereof. As shown in FIGURE 1, when rotor 12 is in its first position base 13' of contact 13 is in electrical contact with the right leaf spring contact 14 and step 24 of rotor 12 rests between contact 13 and the left leaf spring 24 preventing electrical contact between the two elements. The turning of slot 22 such that it is in alignment with the other indicator mark shown in FIG- URE 3 will rotate rotor 12 90 around base 13 of contact 13. In this position base 13' will now be in electrical contact with the left leaf spring and step 24 of rotor 12 will insulate the right leaf spring from contact 13.

It is therefore seen that merely by turning offset 17 through approximately 90 a switching from one contact to another is effected. The flat portion 20 of rotor 12 rests against a leaf spring and thereby prevents rotation of the rotor due to vibrations or other unwanted causes. Also, because rotor 12 is offset from the longitudinal axis of case 11, it can not rotate more than 90 from its set position without hitting the side of case 11. It is therefore seen that the unique configuration of rotor 12 enables it to act as a locking means, a detent means, and a leaf spring contact biasing means.

Although this invention has been described with respect to a particular embodiment thereof, it is not to be so limited, as changes and modifications may be made there in which are within the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A miniature switch comprising: a dielectric case, a dielectric rotor having a cam surface mounted for rotation within said case, a first contact resting upon said rotor, a second and a third contact mounted in said case so that rotation of said rotor in one direction will cause electrical contact between said first contact and said second contact and prevent contact between said first contact and said third contact, and rotation in the opposite direction will cause electrical contact between said first contact and said third contact and prevent electrical contact between said first and second contacts.

2. The switch of claim 1 wherein said case has an axis of symmetry and said rotor is mounted offset from said axis of symmetry.

3. The switch of claim 2 wherein said rotor has an offset portion for mounting said rotor in said case.

4. The switch of claim 3 wherein said rotor has flat sides along its length.

5. The switch of claim 4 wherein said third contact rests upon an instep portion of said rotor and said third contact has a base portion which is larger than said instep portion.

6. The switch of claim 5 wherein said third contact and the axis of rotation of said instep portion are offset from rotor.

, References Cited by the Examiner UNITED STATES PATENTS 2,735,916 2/1956 Arnejo 200l55 2,739,208 3/ 1956 Ullrich 200-6 X ROBERT K. SCHAEFER, Primary Examiner. H. HOHAUSER, Assistant Examiner. 

1. A MINIATURE SWITCH COMPRISING: A DIELECTRIC CASE, A DIELECTRIC ROTOR HAVING A CAM SURFACE MOUNTED FOR ROTATION WITHIN SAID CASE, A FIRST CONTACT RESTING UPON SAID ROTOR, A SECOND AND A THIRD CONTACT MOUNTED IN SAID CASE SO THAT ROTATION OF SAID ROTOR IN ONE DIRECTION WILL CAUSE ELECTRICAL CONTACT BETWEEN SAID FIRST CONTACT AND SAID SECOND CONTACT AND PREVENT CONTACT BETWEEN SAID FIRST CONTACT AND SAID THIRD CONTACT, AND ROTATION IN THE OPPOSITE DIRECTION WILL CAUSE ELECTRICAL CONTACT BETWEEN SAID FIRST CONTACT AND SAID THIRD CONTACT AND PREVENT ELECTRICAL CONTACT BETWEEN SAID FIRST AND SECOND CONTACTS. 